On this page

Preview Plugins

Preview plugins extend Seer's native viewing engine, enabling instant previews for file formats not supported out of the box (such as CAD drawings, EPUB ebooks, 3D assets and specialized formats).

1. Online Installation (Available Tab)

The built-in plugin repository allows you to browse and install verified plugins directly:

  1. Open Seer settings (Ctrl+, or right-click the system tray icon and select Settings).
  2. Navigate to Settings > Viewers and switch to the Available tab.
  3. Browse the list or use the search bar to locate the plugin you need.
  4. Click Install.
  5. Click Tasks to monitor download progress and installation status.
  6. Click Okay to save settings and use the plugin.

Note: If an installation fails due to a locked file or temporary network issue, restart Seer and click Retry in the Tasks panel.

2. Local Installation (Local Tab)

Download Plugins

  • Recommended: Visit Plugin Downloads - Viewers to easily find and download official packaged viewer extensions (.zip).
  • Browse plugin releases on GitHub. Choose the plugin you need and check its release notes for Seer version requirements. Under Assets, download the plugin ZIP, not GitHub's Source code archive. Different plugins may be listed under different releases.

If in-app installation is slow or unavailable, use this manual download instead. You can import the ZIP directly without extracting it.

Install the Download

If you already have a package or developed your own:

  1. In Settings > Viewers, switch to the Local tab.
  2. Click + below the list.
  3. Select your plugin file:
    • Packaged Plugin: A .zip archive containing the plugin assets.
    • Plugin Manifest: A plugin.json definition file.
  4. Seer prepares the package and selects it in the appropriate settings page.
  5. Review its settings, then click Okay to save and activate it. Cancel discards the import.

If importing a manifest, keep it alongside the executable and other package files; the JSON alone is not a complete plugin.

3. Managing Installed Plugins

Priority Ordering

If multiple plugins support the same file extension, Seer checks viewer type priority first: DLL plugins take precedence over conversion plugins. - Within the same priority level, plugins are checked in top-to-bottom order. Drag items in the Local table to change that order. - Moving a plugin above one of a higher-priority type does not override the type priority.

Enabling / Disabling

  • Select a plugin and toggle Enabled in its details, then save settings.

Customizing Format Overrides

  • Select a plugin in the table to display its details on the right panel.
  • Under File Formats, you can add, modify, or remove extensions handled by the plugin.
  • Adjust CLI arguments or execution parameters if needed.

Uninstalling

  • Select the plugin and click Delete in the details pane. Click Okay to commit removal and clean up its managed package files.

Important Notes

  • Package Files: Seer copies imported packages into its managed plugin directory. Do not move or edit the deployed files there.
  • Extension Matching: File extensions are case-insensitive (e.g., .PNG and .png match identically).
  • Source Files: Keep the downloaded package intact until installation finishes.
  • Performance: Keep only the plugins you actively use enabled to maintain Seer's fast startup and minimal memory footprint.